The present invention relates to welding and, more particularly, to friction welding of workpieces of similar and/or dissimilar materials and having similar or dissimilar cross sections.
Frictional welding techniques are known and, in general, they employ thermal energy derived from a transformation of mechanical energy by a frictional process for the generation of heat to achieve the joining together of various materials. Thus, a friction welding process generally includes causing relative rotation between workpieces to be joined together, as well as urging together the respective workpieces at mutually engaging surfaces thereof. Such relative movement between such surfaces results in the generation of sufficient heat at the interface between such surfaces to enable them to be press-forged together and to provide a bond at the weld interface.
The prior art relating to frictional welding specifies limitations requiring that the workpieces be of identical configuration and/or size or that the smaller of the workpieces be completely circumscribed by the larger. Additionally, such prior art suggests that formation of a strong bond will be prevented by oxidation of a portion of one of the faying surfaces due to its exposure to the ambient atmosphere if such portion is out of contact with the other faying surface at some time during the carrying out of a frictional welding process.